A battery management system (BMS) of a vehicle which monitors failure of a vehicle battery system may be configured to cut off a battery relay and stop to assure safety of the system. For example, when electricity leaks to a vehicle chassis due to leakage or deterioration of a battery, a short circuit of a cable, an insulation resistance breakdown in high voltage systems or electronic parts in the vehicle, etc., there is a need to alert a driver of the vehicle state and to stop the vehicle to assure safety against an electronic shock to passengers. The insulation resistance of about 500 Ω/V or greater is required legally and for a 200 V battery, the insulation resistance should be maintained at about 100 kΩ or greater. Therefore, there is a need to maintain insulation resistance at about 300 kΩ or greater in consideration of a margin or inhibit the driving of the vehicle at the insulation resistance less than that.
However, the existing battery management system only determines the insulation resistance breakdown without determining positions of electronic parts broken due to insulation resistance breakdown while driving the vehicle to cut off the battery relay, and therefore may not determine which one of the electronic parts fails. Further, when the vehicle receives after service, a service center measures the insulation resistance thereof while forcibly operating high voltage parts, and the like, one by one to determine the broken electronic parts. Additionally, since the cause of the failure may be difficult to determine after a substantial amount of time, incorrect service may be performed thus potentially leading to failure of other components.